Objective To investigate the effects of high-risk human papillomavirus 16 E6 protein(HPV16 E6 protein)on invasion and migration of cervical cancer SiHa cells via regulating the expression of expression miR-23a.Methods Tissue samples from 100 patients with cervical cancer HPV-negative,100 HPV-positive patients,and 100 paracancerous normal tissues were collected;cervical cancer SiHa cells were divided into blank group,E6 overexpression group,negative transfection group,and E6 + miR-23a mimics group.The expression of miR-23a and HPV16 E6 mRNA were detected by qRT-PCR;MTT assay was used to detect the cell proliferation inhibition rate;flow cytometry to detect the apoptosis;Transwell chamber assay to detect cell invasion,and scratch test to detect the ability of cell migration.The expression of HPV16 E6,apoptosis related proteins(Caspase-3,Bax,Bcl-2),and migration related proteins(MMP-2,MMP-9)was detected by WB.Results The expression level of miR-23a was decreased in cervical cancer tissues,and that was lower in HPV positive cervical cancer tissues.Overexpression of E6 decreased the expression level of miR-23a,cell proliferation inhibition rate,apoptosis rate,Caspase-3 and Bax protein expression,and increased the expression of Bcl-2 protein,scratch healing rate,inva-sion cell number,MMP-2,MMP-9 protein expression(P<0.05);miR-23a mimics reversed the effects of E6 overexpression on the above indicators.Conclusion HPV16 E6 promotes the invasion and migration of cervical cancer cells,which may be related to the regulation of miR-23a expression.

OBJECTIVERisk assessment and risk control for occupational exposure to chemical toxicants were performed on an isophorone nitrile device with an annual production of 5,000 tons, based on improved Singaporean semi-quantitative risk assessment method, with consideration of actual situation in China and in the present project.

METHODSWith the use of engineering analysis and identification of occupational hazards in the improved Singaporean semi-quantitative risk assessment method, hazard rating (HR) and risk assessment were performed on chemical toxicants from an isophorone nitrile device with an annual production of 5,000 tons.

RESULTSThe chemical toxicants in the isophorone nitrile device were mainly isophorone, hydrocyanic acid, methanol, phosphoric acid, sodium hydroxide, and sodium cyanide; the HR values were mild hazard (2), extreme hazard (5), mild hazard (2), mild hazard (2), moderate hazard (3), and extreme hazard (5), respectively, and the corresponding exposure rating (ER) values were 2.09, 2.72, 2.76, 1.68, 2.0, and 1.59, respectively. The risk of chemical toxicants in this project was assessed according to the formula Risk = [HR×ER](1/2). Hydrocyanic acid was determined as high risk, sodium hydroxide and sodium cyanide as medium risk, and isophorone, methanol, and phosphoric acid as low risk. Priority in handling of risks was determined by risk rating. The table of risk control measure was established for pre-assessment of occupational hazards.

CONCLUSIONWith risk assessment in this study, we concluded that the isophorone nitrile device with 5,000 ton annual production was a high-occupational hazard device. This device is a project of extreme occupational hazard. The improved Singaporean semi-quantitative risk assessment method is a scientific and applicable method, and is especially suitable for pre-evaluation of on-site project with no analogy.

Cyclohexanones ; Humans ; Nitriles ; Occupational Exposure ; prevention & control ; Risk Assessment